Method for fabricating a titanium-containing silicon oxide material with high thermal stability and applications of the same

Abstract

The present invention discloses a method for fabricating a titanium-containing silicon oxide material with high thermal stability and applications of the same, wherein a titanium source, a silicon source, an alkaline source, a template molecule and a peroxide are formulated into an aqueous solution; the aqueous solution reacts to generate a solid product; the solid product is separated from the aqueous solution with a solid-liquid separation process and dried; the solid product is calcined to obtain a titanium-containing silicon oxide material with high specific surface area. The titanium-containing silicon oxide material fabricated by the present invention has high thermal stability. Therefore, it still possesses superior catalytic activity after calcination. The titanium-containing silicon oxide material can be used to catalyze epoxidation of olefin and is very useful in epoxide production.

What is claimed is: 
     
       1. A method for fabricating a titanium-containing silicon oxide material with high thermal stability, comprising steps:
 mixing a titanium source, a silicon source, an alkaline source, a template molecule, a solvent and a peroxide to form an aqueous solution; 
 enabling a co-condensation reaction of said aqueous solution without using a hydrothermal treatment, undertaking a solid-liquid separation process of said aqueous solution, and undertaking a drying process of a solid product separated from said aqueous solution; and 
 undertaking a calcination process of said solid product acquired in said solid-liquid separation process to obtain a titanium-containing silicon oxide material having Formula (I) in an anhydrous state:
     x TiO 2 (1− x )SiO 2   (I)
 
 
 wherein x ranges from 0.00001-0.5; 
 wherein said titanium-containing silicon oxide material has an average pore size of 10 angstroms or more; 
 wherein said titanium-containing silicon oxide material has a pore size of 90% or more of the total pore volume of 5 to 200 Å; and 
 wherein said titanium-containing silicon oxide material has a specific pore volume of 0.2 cm 3 /g or more; 
 wherein said template molecule is a nitrogen-containing molecule having a formula: R 1 NR 2 R 3  or a quaternary ammonium salt-containing molecule having a formula: [NR 1 R 4 R 5 R 6 ] + , or a combination thereof, and wherein R 1  is a functional group containing a straight hydrocarbon chain or a branch hydrocarbon chain; each of said straight hydrocarbon chain and said branch hydrocarbon chain has 2-36 carbon atoms; each of R 2  and R 3  is a hydrogen atom, an alkyl group, or a phenyl group; each of R 4 -R 6  is an alkyl group or a phenyl group; each of said alkyl group has 1-8 carbon atoms; and each of said phenyl group has 6-8 carbon atoms; 
 wherein said titanium-containing silicon oxide material has at least one peak showing an interplanar spacing (d) of larger than 18Å, or no peak showing an interplanar spacing (d) in a X-ray diffraction (XRD). 
 
     
     
       2. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 1 , wherein said titanium source is a titanate, an inorganic titanium source, or a combination thereof; said silicon source is an amorphous silicon dioxide, an alkoxysilane, a silicate, or a combination thereof; said alkaline source is an inorganic alkaline, an organic alkaline, a counter ion that is an anion containing hydroxyl groups and also an organic molecule able to function as a template, or a combination thereof; said template molecule is a cation surfactant, an anion surfactant, a non-ionic surfactant, an ampholytic surfactant, or a combination thereof; said solvent is selected from a group consisting of methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, vinyl butanol, allyl butanol, butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, amyl alcohol, cyclohexanol, benzyl alcohol, diols, and combinations thereof; said peroxide is hydrogen peroxide or an organic peroxide. 
     
     
       3. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 2 , wherein said titanate is selected from a group consisting of tetramethyl titanate, tetraethyl titanate, tetrapropyl orthotitanate, tetra isopropyl titanate, tetrabutyl orthotitanate, tetra sec-butyl titanate, tetrabutyl isotitanate, tetra tert-butyl titanate, tetra(2-ethylhexyl) titanate, tetraoctadecyl orthotitanate, and combinations thereof; said inorganic titanium source is selected from a group consisting of titanium trichloride, titanium tetrachloride, titanium tribromide, titanium tetrabromide, titanium triiodide, titanium tetraiodide, titanium sulfate, titanium dioxide, and combinations thereof. 
     
     
       4. The method for fabricating a titanium-containing silicon oxide material with high theimal stability according to  claim 2 , wherein said amorphous silicon dioxide is selected from a group consisting of smoked silica, fumed silica, silica gel, silica sol, and combinations thereof; said alkoxysilane is selected from a group consisting of tetramethylorthosilicate, tetraethylorthosilicate, tetrapropylorthosilicate, alkyltrialkoxysilanes, dialkyldialkoxysilanes, trialkylmonoalkoxysilanes, and combinations thereof; said silicate is selected from a group consisting of water glass, potassium silicate, magnesium silicate, calcium silicate, and combinations thereof. 
     
     
       5. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 2 , wherein said organic alkaline is selected from a group consisting of ammonium hydroxide, pyridines, imidazoles, benzimidazoles, histidines, and combinations thereof; said inorganic alkaline is selected from a group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, and combinations thereof; said counter ion is an anion containing hydroxyl groups and also an organic molecule able to function as a template, selected from a group consisting of dodecyl trimethyl ammonium hydroxide, tetradecyl dimethyl benzyl ammonium hydroxide, cetyltrimethylammonium hydroxide, hexadecyl tributyl ammonium hydroxide, benzyltrimethylammonium hydroxide, dimethyldidodecylammonium hydroxide, hexadecylpyridinium, trimethyloctadecylammonium hydroxide, and combinations thereof. 
     
     
       6. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 1 , wherein said template molecule is selected from a group consisting of dodecylamine, n-tetradecylamine, hexadecylamine, octadecylamine, tetradecyl dimethyl amine, hexadecylmethylamine, hexadecyldimethylamine, dodecyl trimethyl ammonium, tetradecyl dimethyl benzyl ammonium, cetyltrimethylammonium, hexadecyl tributyl ammonium, benzyltrimethylammonium, dimethyldidodecylammonium, hexadecylpyridinium, trimethyloctadecylammonium, and combinations thereof. 
     
     
       7. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 2 , wherein said organic peroxide has a formula: R—O—O—H, wherein R denotes an acyl group or a hydrocarbon group, which has 1-20 carbon atoms. 
     
     
       8. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 7 , wherein said R group has 1-10 carbon atoms. 
     
     
       9. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 7 , wherein said R group is selected from a group consisting of acyl groups, alkyl groups, cycloalkyl groups, secondary or tertiary alkyl groups, hydrocarbon groups, cycloalkenyl groups, aralkyl groups, and aralkenyl groups. 
     
     
       10. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 7 , wherein said organic peroxide is selected from a group consisting of peroxyformic acid, peroxyacetic acid, peroxypropionic acid, peroxystearic acid, peroxypalmitic acid, peroxylauric acid, meta-chloroperoxybenzoic acid, ethylbenzene hydroperoxide, cumene hydroperoxide, tertiary butyl hydroperoxide, or cyclohexyl hydroperoxide, tetralin hydroperoxide,methyl ethyl ketone peroxide, methylcyclohexene hydroperoxide, and combinations thereof. 
     
     
       11. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 1 , wherein said peroxide is generated in a reaction of barium oxide and dilute sulfuric acid, a hydrolysis reaction of ammonium persulfate, a catalytic reaction of hydrogen and oxygen in a metal catalyst, a catalytic reaction of aldehyde, alkyl, or aromatic alkyl in air or oxygen with or without a catalytic agent. 
     
     
       12. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 1 , wherein a molar ratio of titanium to silicon in said aqueous solution is 0.00001-1; a molar ratio of said template molecule to a sum of titanium and silicon is 0.01-2; a weight ratio of said solvent to water is 0-5; a molar ratio of said peroxide to a sum of titanium and silicon is 0.001-5; a molar ratio of said template molecule to water is 0.001-1; a molar ratio of said alkaline source to said template molecule is 0.1-6. 
     
     
       13. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 12 , wherein a molar ratio of titanium to silicon in said aqueous solution is 0.00008-0.5; a weight ratio of said solvent to water is 0.01-3; a molar ratio of said peroxide to a sum of titanium and silicon is 0.01-3; a molar ratio of said template molecule to water is 0.005-0.5; a molar ratio of said alkaline source to said template molecule is 1-4. 
     
     
       14. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 1 , wherein said aqueous solution reacts at a temperature of −20-200° C. for 0.5-180 hours, and whereafter said drying process of said solid product separated from said aqueous solution is continuously undertaken at a temperature of 30-120° C. for 0.5-6 hours. 
     
     
       15. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 1 , wherein said calcination process is undertaken at a temperature of 300-800° C. for 1-9 hours. 
     
     
       16. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 15 , wherein said calcination process is undertaken at a temperature of 350-650° C. for 3-6 hours. 
     
     
       17. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 1  further comprising at least one of following steps:
 performing a silylation treatment on said titanium-containing silicon oxide material at a temperature of 25-200° C. for 0.5-3 hours; and 
 impregnating a transition metal into said titanium-containing silicon oxide material, wherein said transition metal has a concentration of 0.01-10wt % in a total weight of said titanium-containing silicon oxide material. 
 
     
     
       18. The method for fabricating a titanium-containing silicon oxide material with high thermal stability according to  claim 17 , wherein said transition metal has a concentration of 0.005-5wt % in a total weight of said titanium-containing silicon oxide material. 
     
     
       19. A method for fabricating an epoxide, comprising a step:
 providing a titanium-containing silicon oxide material with high thermal stability fabricated according to  claim 1  as a catalyst to enable a reaction of olefin and oxidant to form an epoxide. 
 
     
     
       20. The method for fabricating an epoxide according to  claim 19 , wherein said olefin is selected from a group consisting of mono-olefin compounds, di-olefin compounds, and poly-olefin compounds; said oxidant is an organic peroxide or a hydrogen peroxide; said mono-olefin compound is selected from a group consisting of ethylene, propylene, 1-butene, isobutene, 1-hexene, 2-hexene, 3-hexene, 1-octene, 1-decene, styrene, and cyclohexene; said di-olefin compound is butadiene or isoprene; said organic peroxide is selected from a group consisting of ethylbenzene hydroperoxide, cumene hydroperoxide, tertiary butyl hydroperoxide, and cyclohexyl hydroperoxide. 
     
     
       21. The method for fabricating an epoxide according to  claim 19 , wherein a molar ratio of said olefin to said oxidant ranges from 1:100 to 100:1; said olefin and said oxidant react at a temperature of 0-200° C.; said olefin and said oxidant react at a pressure greater than a pressure keeping all reactants in a liquid state; a reaction time of said olefin and said oxidant is within 1 minute-48 hours. 
     
     
       22. The method for fabricating an epoxide according to  claim 21 , wherein a molar ratio of said olefin to said oxidant ranges from 1:10 to 10:1; said olefin and said oxidant react at a temperature of 25-150° C.; said olefin and said oxidant react at a pressure of 1-100 atm; a reaction time of said olefin and said oxidant is within 5 minute-8 hours.